Convert Houdini Matrix To Blender Matrix?
Thanks for the replies. I also got replies on BlenderArtists as well. I finally found a solution that works for me so I thought i'd post it here for others to use.

Run this code in the Blender default scene and the camera will jump from one location to another. The new location is defined by the string that holds the Houdini matrix.

import bpy, math
from mathutils import Vector,Matrix

def applyTransform(sMatrix, passedOb):
    if passedOb != None:
        tmp = eval(sMatrix)
        mtx = Matrix(tmp)
        passedOb.location = [mtx[3][0],-mtx[3][1],mtx[3][2]]        # Flip Z and Y axis.
        mtx.transpose()                                             # From BL Stack user.
        rot_x_neg90 = Matrix.Rotation(math.pi/2.0, 4, 'X')          # From Kastoria.
        passedOb.matrix_world = rot_x_neg90 * mtx                   # From Kastoria.

# Matrix string from Houdini object.
s = "[[0.900496, 3.27826e-007, -0.434865, 0], [-0.117881, 0.962558, -0.244102, 0], [0.418583, 0.271075, 0.866779, 0], [5.32776, 2.57303, 7.33473, 1]]"
ob = bpy.data.objects.get("Camera")
applyTransform(s,ob)